This is generally known as the ApoE4 allele of ApoE and is associated with increased risk of Alzheimer's. 20-25% of individuals are heterozygous for this variant, and 1-2% are homozygous. Data from Khachaturian et al. suggests an average 7% of all individuals developed Alzheimer's by the age of 80; when this is split by ApoE4 status: 10% of ApoE4 heterozygotes (3% increased attributable risk), 40% of ApoE4 homozygotes (33% increased attributable risk), and 5% of non-carriers (2% decreased attributable risk). Notably, their model suggests 70-75% of people would eventually develop Alzheimer's by the age of 100 regardless of ApoE4 genotype (and 25-30% are resistant, regardless of genotype), but that ApoE4 variants shift the disease onset to occur significantly earlier (4 years earlier for heterozygous carriers, 13 years for homozygotes).

This variant (also called C3F) is common in Europeans (10.2% allele frequency), and is associated with age-related macular degeneration. In the US, 1.5% of adults over 40 have the disease, but the incidence increases strongly with age (>15% in women over 80). Assuming an average lifetime risk of ~10%, heterozygous individuals have a ~13% risk and homozygous have ~20%.

Known as the "Marburg I" polymorphism, this variant is associated with increased risk of coronary heart disease (CHD) in individuals with elevated cholesterol, triglyceride, and fibrinogen levels (5-fold risk of a CHD event, compared to 2-fold risk increase in people with the same risk factors but do not have this variant). In individuals without these elevated levels, however, carriers of the variant do not appear to have any increased risk of CHD.

This variant was reported to be associated with autoimmune disease when homozygous. However, a later publication has contradicted this result, finding no significant association between this variant and autoimmune disease in a very large cohort.

This variant was initially reported to be a risk factor for glaucoma, but subsequent reports have failed to find a statistically significant association. It may have a modifier effect, with carriers of the variant having lower intraocular pressure on average -- pressures that might be considered normal in other individuals would be abnormally high for carriers of this variant.

This variant is implicated in partial and profound biotinidase deficiency. Alone, this variant is estimated to have a 52% loss of enzymatic activity. This variant is often found with A171T, and together they are reported to cause profound deficiency. Notably there is a report of asymptomatic double-mutant adults, so symptoms may have variable penetrance. This variant is found compound heterozygously with more serious mutations in cases of partial biotinidase deficiency.

This variant represents the PiS variant in alpha-1-antitrypsin deficiency where a homozygous individual has 60% enzymatic activity. This variant alone is unlikely to much effect, but 3-4% of heterozygotes are compound heterozygous with the more severe PiZ variant, which is associated with an increased risk of emphysema and COPD.

This common variant has been associated with arterial stiffness and, in Japanese, a small increased risk of myocardial infarction (MI, a.k.a. heart attack). This last observation supported a dominant effect for this variant and, assuming a lifetime risk of 15% for MI, we estimate carriers have an additional risk of 0.5-3%.

This common variant (HapMap allele frequency of 31.3%) in a protein involved in folate (B9) and cobalamin (B12) metabolism and is often reported as "MTRR I22M" (an alternative transcript position). Mothers homozygous for this variant are associated with having around a increased chance of a child with Down syndrome (risk of 0.4%, average risk in population is 0.25%). Notably, age plays a far larger role in the rate of Down syndrome (risk is 4.5% for a mother 45-years-of-age), and it is unknown how this variant may combine with the effect of age. There are conflicting reports associating this variant with incidence of neural tube defects, possibly when combined with MTHFR A222V.

Causes Adenosine Deaminase Deficiency in a recessive manner. Most of the time individuals do not report symptoms, but when symptoms do exist they to be post-exercise symptoms of muscle weakness, muscle pain, and getting tired more quickly.

Severe variants in this gene are associated with holoprosencephaly disorders when combined with loss-of-function variants in SHH. Haploinsufficiency was identified in some families with this condition. It is unclear how likely this variant is to occur in combination with an SHH variant, or what phenotypic effect the variant would have on its own.

Associated with increased risk of prostate cancer in individuals who already have a family history of prostate cancer, but studies have been unable to replicate this finding in sporadic (non-familial) prostate cancer cases.

This is a common variant was first reported as a polymorphism. It has since had mixed associations with cancer: Storey et al. conclude a 7x *increased* risk of HPV cancer for homozygotes vs hets, but Jones et al. find a 1.98x *decreased* risk for colorectal cancer. This variant may have significant impact on particular cancers, but it is unclear what effect it has on the overall burden of cancer.

There have been some hypotheses that this variant contributes to causing hereditary hemochromatosis, possibly as a compound heterozygote, but some others treat it as a polymorphism. Cys282Tyr is the classic causal variant and itself has very low penetrance. Mouse studies indicates this variant has a similar but weaker effect; if it has any effect at all its penetrance may be quite low and/or require modifier alleles.

This variant is associated with a slightly increased risk of tuberculosis. It is unclear whether it is itself causal, or in linkage disequilibrium with some other causal variant that has a stronger effect.

This common variant may have a small pathogenic effect by contributing to cortisone reductase deficiency (a rare abnormality) when homozygous and combined with a serious pathogenic variant. The same authors have tested and ruled out a contribution to polycystic ovary syndrome (similar phenotype, more common disease).

This variant (a.k.a S149C) was found as a compound heterozygote (with M130T) in a male newborn of European descent with isobutyryl-CoA dehydrogenase deficiency (identified by newborn screening). Lack of controls means that significance cannot be established and allele frequency cannot be estimated. Oglesbee et al. comment that IBD-deficiency may be relatively benign, most cases identified by newborn screening have remained asymptomatic, but Ferreira et al. report a symptomatic individual homozygous for this variant.

rs1544410 is a Vitamin D Receptor (VDR) single nucleotide polymorphism. It is unlikely that it has functional significance because it is located in an intron (Liu et. al.), but it is in strong linkage disequilibrium with rs731236 (Dvornyk et al), which is located in an exon.

This recessive protective variant confers resistance to norovirus (which causes stomach flu). 20% of Caucasians and Africans are homozygous for this variant and are "non-secretors": they do not express ABO blood type antigens in their saliva or mucosal surfaces. Most strains of norovirus bind to these antigens in the gut, and so this non-secretor status confers almost total resistantance to most types of norovirus. There are notable exceptions, some strains of norovirus bind a different target and are equally infectious for secretors and non-secretors.

This variant is associated with some protective effects for prion disease -- individuals homozygous for this variant are less susceptible to Creutzfeldt-Jakob, and Papua New Guinea individuals heterozygotes at this site are less susceptible to kuru.

Associated with a decreased risk for age related macular degeneration (ARMD). Homozygotes for this have a 4-5% decreased attributable risk (3-4% vs. average 8% risk), heterozygotes have slightly lower than average risk (7%). Non-carriers have an increased risk (12-13%). ARMD impairs sharp vision as age progresses. While there is no cure, treatment can slow progression of the disease and environmental factors (smoking and obesity) contribute to higher risk.

This variant is associated with decreased risk of type 2 diabetes. It is unclear whether this variant has additive effects, or acts in a dominant or recessive manner. Assuming diabetes has a lifetime risk of 36%, we estimate a decreased risk of around 1-2% per copy of this variant.

a.k.a Gly1057Asp, insulin receptor substrate-2 IRS2. The rs1805097(G) allele is associated with the Gly, and the (A) allele with Asp.
A longevity study concluded that rs1805097(A;A) individuals were about twice as likely to live over 85 y/o (odds ratio 2.03, CI:1.39-2.99, p = .0003).

This is a frequent pigmentation polymorphism in Europeans that affects function of the Tyrosinase gene. It is associated with blue instead of green eyes and sun sensitivity. For the most part this variant is benign, but many individuals with ocular albinism (which affects only the eyes) carry this variant along with another more severe variant in the same gene.

Tentatively evaluated as benign. Other missense mutations have been reported to cause benign familial neonatal seizures in a dominant manner, this was observed in a PGP participant with no reported family history of this phenotype.

Rare, tentatively classified as benign. Polyphen 2 predicts a damaging effect and other variants in this gene are reported to cause serious diseases, but most of these are dominant and have phenotypes contradicted by the presence of this variant in a healthy PGP participant. Variants reported to cause recessive disease are more severe than this variant (nonsense instead of missense mutations).

This is a polymorphism in a gene associated with Stargardt disease. Although it has a slight detectable effect in functional study, it is common in control groups and is not believed to have any significant pathogenic effect.

Probably benign. This variant was implicated as causing Refsum Disease in a recessive manner, but a subsequent publication noted that all instances were linked with other explanatory mutations. The high allele frequency of this variant in the population (7-13%) contradicts a pathogenic hypothesis.

This variant is associated with "taster" status of PTC, along with 49P and 262A. Due to linkage disequilibrium, the independent effects of positions 296 and 262 is unclear. The presence of 49P confers taster status in a dominant fashion, but in the absence of 49P, the presence of 262A/296V is still positively associated with tasting PTC.

This rare variant is strongly associated with causing colon cancer. Lamlum et al. found an odds ratio of 11.17 for colorectal cancer with multiple adenomas, which seems to indicate a moderate or high penetrance effect.

This is a common variant was first reported as a polymorphism. It has since had mixed associations with cancer: Storey et al. conclude a 7x *increased* risk of HPV cancer for homozygotes vs hets, but Jones et al. find a 1.98x *decreased* risk for colorectal cancer. This variant may have significant impact on particular cancers, but it is unclear what effect it has on the overall burden of cancer.

This variant (also called C3F) is common in Europeans (10.2% allele frequency), and is associated with age-related macular degeneration. In the US, 1.5% of adults over 40 have the disease, but the incidence increases strongly with age (>15% in women over 80). Assuming an average lifetime risk of ~10%, heterozygous individuals have a ~13% risk and homozygous have ~20%.

This common variant has been associated with arterial stiffness and, in Japanese, a small increased risk of myocardial infarction (MI, a.k.a. heart attack). This last observation supported a dominant effect for this variant and, assuming a lifetime risk of 15% for MI, we estimate carriers have an additional risk of 0.5-3%.

Severe variants in this gene are associated with holoprosencephaly disorders when combined with loss-of-function variants in SHH. Haploinsufficiency was identified in some families with this condition. It is unclear how likely this variant is to occur in combination with an SHH variant, or what phenotypic effect the variant would have on its own.

This variant was initially reported to be a risk factor for glaucoma, but subsequent reports have failed to find a statistically significant association. It may have a modifier effect, with carriers of the variant having lower intraocular pressure on average -- pressures that might be considered normal in other individuals would be abnormally high for carriers of this variant.

This variant is associated with some protective effects for prion disease -- individuals homozygous for this variant are less susceptible to Creutzfeldt-Jakob, and Papua New Guinea individuals heterozygotes at this site are less susceptible to kuru.

Associated with increased risk of prostate cancer in individuals who already have a family history of prostate cancer, but studies have been unable to replicate this finding in sporadic (non-familial) prostate cancer cases.

This variant is associated with a slightly increased risk of tuberculosis. It is unclear whether it is itself causal, or in linkage disequilibrium with some other causal variant that has a stronger effect.

Causes Adenosine Deaminase Deficiency in a recessive manner. Most of the time individuals do not report symptoms, but when symptoms do exist they to be post-exercise symptoms of muscle weakness, muscle pain, and getting tired more quickly.

This variant is associated with decreased risk of type 2 diabetes. It is unclear whether this variant has additive effects, or acts in a dominant or recessive manner. Assuming diabetes has a lifetime risk of 36%, we estimate a decreased risk of around 1-2% per copy of this variant.

This common variant (HapMap allele frequency of 31.3%) in a protein involved in folate (B9) and cobalamin (B12) metabolism and is often reported as "MTRR I22M" (an alternative transcript position). Mothers homozygous for this variant are associated with having around a increased chance of a child with Down syndrome (risk of 0.4%, average risk in population is 0.25%). Notably, age plays a far larger role in the rate of Down syndrome (risk is 4.5% for a mother 45-years-of-age), and it is unknown how this variant may combine with the effect of age. There are conflicting reports associating this variant with incidence of neural tube defects, possibly when combined with MTHFR A222V.

This common variant may have a small pathogenic effect by contributing to cortisone reductase deficiency (a rare abnormality) when homozygous and combined with a serious pathogenic variant. The same authors have tested and ruled out a contribution to polycystic ovary syndrome (similar phenotype, more common disease).

This variant represents the PiS variant in alpha-1-antitrypsin deficiency where a homozygous individual has 60% enzymatic activity. This variant alone is unlikely to much effect, but 3-4% of heterozygotes are compound heterozygous with the more severe PiZ variant, which is associated with an increased risk of emphysema and COPD.

This variant is implicated in partial and profound biotinidase deficiency. Alone, this variant is estimated to have a 52% loss of enzymatic activity. This variant is often found with A171T, and together they are reported to cause profound deficiency. Notably there is a report of asymptomatic double-mutant adults, so symptoms may have variable penetrance. This variant is found compound heterozygously with more serious mutations in cases of partial biotinidase deficiency.

There have been some hypotheses that this variant contributes to causing hereditary hemachromatosis, possibly as a compound heterozygote, but some others treat it as a polymorphism. Cys282Tyr is the classic causal variant and itself has very low penetrance. Mouse studies indicates this variant has a similar but weaker effect; if it has any effect at all its penetrance may be quite low and/or require modifier alleles.

This variant, which has a 3.4% allele frequency in 1000 genomes data, is reported to be associated with autoimmune disease when homozygous. The statistical significance of the findings is unclear. Assuming it is pathogenic, we estimate that the relative risk of autoimmune disease in homozygous individuals is around 4x (8% risk vs. an average of 2% risk).

This variant (a.k.a S149C) was found as a compound heterozygote (with M130T) in a male newborn of European descent with isobutyryl-CoA dehydrogenase deficiency (identified by newborn screening). Lack of controls means that significance cannot be established and allele frequency cannot be estimated. Oglesbee et al. comment that IBD-deficiency may be relatively benign, most cases identified by newborn screening have remained asymptomatic, but Ferreira et al. report a symptomatic individual homozygous for this variant.